Motor vehicle differential

ABSTRACT

The invention concerns a motor vehicle differential comprising a case including perforations; differential pinion shafts, each differential pinion shaft having an end accommodated by a perforation; and a cap; wherein the differential pinion shafts are locked in translation relative to the differential case by the cap, the cap being mounted on at least the part of the differential case traversed by the shafts so as to cover at least partially the perforations.

The present invention concerns a motor vehicle differential.

Such a differential is comprised of a differential case that can bedriven by a ring ear integral with this case, satellites rotatablymounted in the case via shafts passing through it that are immobilizedin translation relative to the case, and two sun gears, rotatablymounted in the case, in engagement with the satellites.

Various solutions have been proposed in the past for blockingtranslation of the satellite shafts in the case.

One of these solutions provides for the use of a ring seated in areception groove made in each perforation of the case body through whichthe corresponding satellite shaft is introduced. This solutionnecessitates not only machining the grooves but also has thedisadvantage that the grooves greatly weaken the strength of thedifferential case body.

Another solution consists in providing a specific locking screw for eachsatellite shaft. This solution has the major inconvenience of beingbulky.

Yet another solution provides for the use of a safety pin for eachsatellite shaft, partially implanted in the body of the differentialcase while projecting into the perforation of this body that permitspassage of the satellite shaft. This solution requires machining theperforations for passage and implantation of the safety pins.

A solution is also known that utilizes separate plates detachablyfastened to the body of the differential case and each having a tonguesealing the corresponding perforation in the differential case forpassage of the satellite shaft. However, the use of separate plates isdependent on the assembly system of the driving ring gear of thedifferential case.

The present invention proposes to eliminate the above shortcomings ofthe various known solutions that permit blocking translation of thesatellite shafts in the differential case.

For this purpose, the invention proposes a motor vehicle differentialcomprised of a differential case that can be driven by a ring gearintegral with the case, satellites rotatably mounted in the case viashafts traversing the case that are immobilized in translation relativeto the case, and two sun gears rotatably mounted in the case and engagedwith the satellites, and which is characterized in that the satelliteshafts are immobilized in translation by a cap covering at least thepart of the differential case traversed by the shafts such that thepassage perforations for the shafts made through the peripheral wall ofthe differential case are at least partially covered.

The satellite shaft stopper cap is held in translation on thedifferential case.

The satellite shaft stopper cap preferably covers by conforming to theshape of the major portion of the differential case, and is immobilizedin translation relative to this case by the annular end, opposite fromthe ring gear, supported against the inner race of the axle bearingmounted on a tubular support of the differential case.

According to one embodiment variant, the cap is made of plasticmaterial.

According to another variant, the cap is made from stamped sheet metal.

The invention will be better understood, and other goals,characteristics, details and advantages of it will appear more clearlyin the following explanatory description, with reference to the attacheddrawings, given merely by means of example illustrating an embodiment ofthe invention:

FIG. 1 is an exploded oblique view of a motor vehicle differentialaccording to the invention.

FIG. 2 is an oblique view of the cap of the invention that permitsimmobilizing in translation the satellite shafts of the differential ofFIG. 1.

FIG. 3 is a partial cross section of the cap immobilizing a satelliteshaft.

The motor vehicle differential as shown in the figures comprises adifferential case 1 of general truncated form and a ring drive gear 2 ofthe case 1 detachably fastened to the case 1 by rivets 3 or otheranalogous means such as, e.g., fastening screws.

The differential case I has several perforations 4 passing through itsperipheral wall that are angularly spaced equidistantly around the samecircumference.

The differential is comprised of satellites 5 rotatably mounted in thecase 1 via shafts 6 engaged from the outside in the perforations 4 byhaving their ends respectively accommodated in these perforations. Theopposite end of each satellite shaft 6 located inside of the case 1penetrates into a conjugate perforation 7 of a central cylindricalsupport piece 8.

The differential has two more sun gears 9 accommodated in the case 1 andengaged with the satellites 5.

As represented, the differential case 1 contains four satellites 5mounted respectively on four shafts 6, only three of which are shown,the shafts 6 being located in the same plane and orthogonally withrespect to one another.

Finally, the differential has two axle bearings 6 mounted at its ends inknown fashion.

According to the invention, the satellite shafts 6 are immobilized intranslation in their respective perforations 4 by a means forming cap 11that covers at least the peripheral part of the differential case 1where the perforations 4 are located so as to cover these perforationsat least partially.

The cap 11 preferably covers by conforming to the shape of the majorportion of the differential case 1 and is immobilized in translationrelative to the case 1 by its annular end 11 a, opposite from ring gear2, supported against the inner race 10 a of the bearing 10 mounted on atubular support 1 a of the case 1 and coaxial with the longitudinalshaft of the differential passing through latter's various componentscomprising the case 1, the sun gears 9, the central cylindrical piece 8and the ring gear 2. The annular end 11 b of the cap 11 opposite thepart 11 a can be shaped so as to extend over the external flattenedparts 12 machined on the body of the case 1 parallel to the longitudinalaxis of the differential and into which the perforations 4 respectivelyopen. This annular part thus has its internal face opposite eachflattened part of orifice 4, is plane and is located immediately next tothe latter so as to permit only a very slight play to remain between itand the corresponding end of the satellite shaft 6.

FIG. 2 more particularly represents such a conformation constituted byan internally projecting part 11 c coming above the flattened part 12 ofthe corresponding perforation 4. This figure also shows that the cap 11can be open, i.e., not completely covering the periphery of thedifferential case 1, and that it has two lateral walls or plane parallelsides 11 d that cooperate with two parts of the lateral walls of thiscase for rotationally immobilizing the cap 11 relative to the case 1.

The cap 11 can be made of a plastic material or, according to onevariant embodiment, of stamped sheet metal.

The order of assembly of the different components of the differential isas follows: The sun gears 9 and the satellites 5 are mounted in thedifferential case 1, and the shafts 6 of the satellites 5 are thenmounted from the outside through the perforations 4. The stopper cap 11of the shafts of the satellites 6 then is mounted on the differentialcase 1 before mounting the axle bearings 10.

The cap for stopping translation of the satellite shafts is a relativelysimple, quite inexpensive structure, does not require particularmachining, and is independent of the assembly of the ring gear to thedifferential case; the assembly or disassembly of each satellite shaftand of the internal components of the differential can be done with thering gear assembled to the case.

1. (canceled)
 2. The differential according to claim 5, wherein the cap of the shafts of the satellites is held in translation on the differential case.
 3. The differential according to claim 5, wherein the cap is made of a plastic material.
 4. The differential according to claim 5, wherein the cap is made of stamped sheet metal.
 5. A motor vehicle differential comprising: a differential case, capable of being driven by a ring gear, the case comprising a peripheral wall including perforations and a tubular support; shafts transversing the case, the shafts passing through the perforations in the case; satellites rotatably mounted in the case via the shafts, the shafts being immobilized in translation relative to the case; two sun gears rotatably mounted in the case, the sun gears being in engagement with the satellites; and, a cap having an annular end, the cap covering a portion of the case; wherein the shafts are immobilized in translation by the cap, and the cap at least partially covers the perforations; wherein the cap is immobilized in translation relative to the case by the annular end opposite the ring gear; and, wherein an axle bearing having an inner race is mounted on the tubular support and the annular end of the case is supported against the inner race of the axle bearing.
 6. The differential according to claim 2 wherein the cap is made of a plastic material.
 7. The differential according to claim 2 wherein the cap is made of stamped sheet metal. 